The central nervous system of mammals has a relatively limited ability to generate new neurons during adulthood. However, environmental and hormonal stimuli can increase rates of neurogenesis in certain brain regions, suggesting that such stimuli might be eventually used therapeutically to enhance the repair of damaged or diseased brain regions and restore behavioral function. The research proposed here is the first stage of a research program designed to understand how social stimuli and steroid treatment modify the rate of naturally occurring neurogenesis and how the resultant structural changes in the adult brain relate to behavioral plasticity. Electric fish are used for this research because the neural circuits controlling behavior are very well described, their behavior is known to respond to social and steroidal stimuli and their brain is known to have a high level of structural plasticity during adulthood. To test the hypothesis that social stimulation and glucocorticoid treatment simultaneously affect neurogenesis and social behavior, 1) adult fish will be housed separately and or in pairs [sic], or implanted with cortisol or empty capsule 2) electrocommunication behavior will be assayed by presentation of standard electrical stimuli, and 3) neuronal proliferation in the brain will be determined by examining the distribution of BrdU incorporation and a neural specific protein, Hu. To test the hypothesis that electrocommunication signals from another fish are sufficient to enhance adult neurogenesis, fish will be exposed to conditions in which they receive a) no social interaction, b) normal social interaction, c) social interaction through the electric modality alone or d) stimulation with non-social electrical stimuli, and the distribution of BrdU incorporation will be examined in brain regions within and outside of the electrocommunication system. These pilot studies will serve to identify specific stimuli and brain regions capable of induced neurogenesis in a model system that has great promise for clarifying links between environment, brain plasticity and behavioral function [unreadable] [unreadable]